What is flag in PLC?

Answer 1

In a Programmable Logic Controller (PLC), a flag is a binary indicator used to represent the status of a specific condition or event within the control program. Flags can be set (turned on) or reset (turned off) based on the outcomes of logical operations or system states, allowing for decision-making in automation processes. They help manage the flow of operations, enabling the PLC to execute tasks based on the current state of the system. Flags are often utilized in conjunction with timers, counters, and other control elements.